Type of Compressors

[cool king2007]

Good day everybody,
Could you tell me what is the difference between single stage compressor and booster?
Thanks & Regards

[DTLarca]

A booster is simply the low stage compressor of a two stage system.

Usually also requires an oil pump when the boost is a screw compressor.

If the overall compression ratio is 9/1 then the boost will handle as near as possible the square root of the overall compression ratio which would be 3/1 leaving the high stage compressor also to handle a ratio of 3/1. The actual ratios selected by the designers depends more on the required mid and lower saturated evaporating temperatures intended.

But when the absolute suction and discharge pressures are 1 and 9 the boost will have a pressure across it to deliver oil of just 3 bar whereas the high stage will have a pressure drop across it of 6 bar enough to preclude the need for an oil pump.

Sorry - I tried to upload a graphic of the typical pipe circuitry and component layout but the image uploader stalls.